1. Technical Field
The disclosure relates to illumination devices, and particularly to an LED (light emitting diode) lamp with a large light emitting angle.
2. Description of Related Art
The technology of light emitting diodes (LEDs) has been rapidly developed in recent years, allowing expansion of application from indicators to illuminators. With the features of long-term reliability, environment friendliness and lower power consumption, the LED is viewed as a promising alternative for recent light products.
A conventional LED lamp comprises a heat sink and a plurality of LEDs attached to an outer surface of the heat sink to dissipate heat generated by the LEDs. The outer surface of the heat sink is generally planar with the LEDs arranged closely. It is known that a majority of light emitted from LEDs travels in a direction approximately perpendicular to a chip surface thereof. Therefore, such LEDs mounting on the planar outer surface of the heat sink provide only a planar light source, and just provide a narrow illumination area. Therefore, the LEDs need to be arranged in a way such that the lights emitted from different LEDs can cooperatively provide a sufficiently wide illumination area to function as a three-dimensional light source.
It is thus desirable to provide an LED lamp which can satisfy the requirement of wide range illumination.